The invention relates to a machine for cold sawing of elongated, horizontal work pieces, particularly metal work pieces, of the type having a vertical circular saw blade attached to an arm which is pivotable around a horizontal axis, and which is further pivotably connected, through a second pivot at the end of the arm opposite to the first pivot, to an approximately vertically moveable device by which the arm can be raised and lowered.
Such sawing machines are called vertical saws even though the saw blade does not move exactly vertically with respect to the work piece but moves in a circular arc around the swinging pivot. For cold sawing of elongated work pieces such as profiled metal, bars, rods, or tubes, the diameter of cross dimension of which does not exceed the diameter of the saw blade, it is advantageous if while the saw blade is being lowered it is kept centrally over the work piece which is being sawed. This applies both to cuts which are perpendicular to the longitudinal axis of the work piece and cuts which are oblique to it. A known means of assuring this is to shift the chuck jaws by which the work piece is held, in such a way, (depending on the width of the work piece) as to keep the work piece centered underneath the saw blade. This method of shifting the work piece is however costly and requires individual measurement and adjustment, since the chuck jaws which afford the contact surfaces must be moved together.
In addition, with these known saws, the size of the work pieces is limited, since they cannot be wider than the diameter of the saw blade.
An object of the instant invention is to improve a machine of the above-described type, such that the saw blade remains centered over the work piece under conditions of a fixed contact surface and different work piece widths. A further object of the invention is to provide a machine of the above-described type which can cut through work pieces of greater width than the diameter of the saw blade.